Linear cutting staplers are widely used in surgical operations such as wound closure and the closure and excision of internal tissues. A typical linear cutting stapler as disclosed in U.S. Pat. No. 5,129,570 performs two functions of stapling and cutting, to remove the redundant tissues while stapling the wound. This kind of linear cutting stapler generally includes two jaws (i.e., an upper jaw and a lower jaw), closing handles (i.e., an upper handle and a lower handle) for closing the upper jaw and the lower jaw, an anvil and a staple cartridge arranged opposite to each other at the distal ends of the upper jaw and lower jaw respectively, a firing piece and a cutter pushing rod provided with a cutter at its distal end which are arranged in the staple cartridge and can simultaneously move relative to the staple cartridge, and a button for driving the firing piece and the cutter pushing rod to move. Staples are arranged inside the staple cartridge. The firing piece successively pushes the staple pushers in sequence which then push the staples to the anvil, and the cutter cuts off the tissues between the staple cartridge and the anvil.
In the prior art, the linear cutting stapler can be used repeatedly by replacing the staple cartridge. During clinical use, the tissues need to be cut and sutured more than once, thus the staple cartridge requires to be replaced repeatedly. That is to say, while the surgeon finishes one set of cutting and suturing actions, firstly, reset the stapler, and then open the upper jaw and the lower jaw; secondly, withdraw the stapler from the surgical spot and then replace the staple cartridge for the linear cutting stapler continuing the next set of cutting and suturing operations.
However, since some careless or inexperienced surgeons may fire the stapler without replacing the used staple cartridge, medical accidents will occur, namely, cutting the tissues without suture. To prevent such accidents from happening, a safety mechanism preventing the second firing action should be added in the linear cutting stapler to avoid medical accidents caused by the misoperation of surgeons.